:root {
  --primary: #004581;
  --primary-dark: #003463;
  --primary-light: #e8f0f7;
  --accent: #1a6bb8;
  --text: #1f2937;
  --text-muted: #6b7280;
  --bg: #f5f7fa;
  --card-bg: #ffffff;
  --border: #e2e8f0;
  --success: #16a34a;
  --danger: #dc2626;
  --warn: #b45309;
  --radius: 10px;
  --shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
}

* { box-sizing: border-box; }

html, body {
  margin: 0; padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
}

.container { max-width: 1140px; margin: 0 auto; padding: 0 24px; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Parent-site strip */
.parent-strip {
  background: var(--primary-dark);
  font-size: 0.8rem;
}
.parent-strip-inner { padding: 6px 24px; }
.parent-strip a { color: #cfe0ef; }
.parent-strip a:hover { color: #fff; }

/* Header */
.site-header { background: var(--primary); color: #fff; }
.header-inner { display: flex; align-items: center; justify-content: space-between; padding: 16px 24px; }
.brand { display: flex; align-items: center; gap: 10px; color: #fff; font-weight: 700; font-size: 1.15rem; }
.brand:hover { text-decoration: none; opacity: 0.9; }
.brand-icon { background: rgba(255,255,255,0.15); width: 34px; height: 34px; border-radius: 8px; display: flex; align-items: center; justify-content: center; font-size: 1rem; }
.main-nav { display: flex; gap: 28px; }
.main-nav a { color: #e5edf5; font-weight: 500; font-size: 0.95rem; padding: 6px 0; border-bottom: 2px solid transparent; }
.main-nav a:hover, .main-nav a.active { color: #fff; text-decoration: none; border-bottom-color: #fff; }
.nav-toggle { display: none; background: none; border: none; color: #fff; font-size: 1.4rem; cursor: pointer; }
@media (max-width: 720px) {
  .main-nav { display: none; position: absolute; top: 64px; left: 0; right: 0; background: var(--primary-dark); flex-direction: column; padding: 12px 24px; gap: 4px; z-index: 50; }
  .main-nav.open { display: flex; }
  .main-nav a { padding: 10px 0; border-bottom: 1px solid rgba(255,255,255,0.1); }
  .nav-toggle { display: block; }
  .site-header { position: relative; }
}

/* ===== Landing page (distinct from the main Quick-Help homepage) ===== */
.emv-hero {
  background: linear-gradient(135deg, var(--primary) 0%, #002d54 100%);
  color: #fff;
  padding: 72px 0 88px;
}
.emv-hero-inner {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
}
@media (max-width: 820px) { .emv-hero-inner { grid-template-columns: 1fr; } }
.emv-hero .kicker {
  display: inline-block;
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.25);
  border-radius: 999px;
  padding: 5px 14px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 18px;
}
.emv-hero h1 { font-size: 2.6rem; font-weight: 800; line-height: 1.15; margin: 0 0 16px; }
.emv-hero p.lead { color: #d8e6f2; font-size: 1.08rem; max-width: 560px; margin: 0 0 26px; }
.emv-hero .hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.emv-hero .btn-hero {
  display: inline-block;
  background: #fff;
  color: var(--primary);
  font-weight: 700;
  padding: 12px 22px;
  border-radius: 8px;
  font-size: 0.95rem;
}
.emv-hero .btn-hero:hover { text-decoration: none; background: #eef4fa; }
.emv-hero .btn-hero.ghost {
  background: transparent;
  color: #fff;
  border: 1px solid rgba(255,255,255,0.4);
}
.emv-hero .btn-hero.ghost:hover { background: rgba(255,255,255,0.08); }

.emv-hero-visual {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.18);
  border-radius: 14px;
  padding: 20px;
  font-family: 'SFMono-Regular', Consolas, monospace;
  font-size: 0.78rem;
  color: #cfe0ef;
  overflow: auto;
  white-space: pre;
  line-height: 1.6;
}
.emv-hero-visual .tag { color: #7fd0ff; }
.emv-hero-visual .len { color: #ffd479; }
.emv-hero-visual .desc { color: #9adf9a; }

.emv-section { padding: 56px 0; }
.emv-section h2 { font-size: 1.6rem; margin: 0 0 8px; color: #0f172a; }
.emv-section p.section-lead { color: var(--text-muted); max-width: 640px; margin: 0 0 32px; }

.tool-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
@media (max-width: 900px) { .tool-cards { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 640px) { .tool-cards { grid-template-columns: 1fr; } }

.tool-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
}
.tool-card .card-icon {
  width: 44px; height: 44px; border-radius: 10px;
  background: var(--primary); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.2rem; font-weight: 700; margin-bottom: 16px;
}
.tool-card h3 { margin: 0 0 8px; font-size: 1.15rem; }
.tool-card p { color: var(--text-muted); font-size: 0.92rem; margin: 0 0 18px; flex-grow: 1; }
.tool-card .open-link { font-weight: 700; color: var(--primary); }
.tool-card.coming-soon { opacity: 0.6; }
.tool-card .badge {
  display: inline-block; font-size: 0.7rem; font-weight: 700; text-transform: uppercase;
  background: var(--primary-light); color: var(--primary); padding: 3px 9px; border-radius: 999px;
  margin-bottom: 12px; align-self: flex-start;
}

.reference-note {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px 26px; box-shadow: var(--shadow);
}
.reference-note h3 { margin: 0 0 8px; font-size: 1.05rem; }
.reference-note p { margin: 0; color: var(--text-muted); font-size: 0.92rem; }

/* Footer */
.site-footer { border-top: 1px solid var(--border); padding: 28px 0 40px; margin-top: 20px; text-align: center; color: var(--text-muted); font-size: 0.9rem; }
.site-footer p { margin: 4px 0; }
.site-footer a { color: var(--primary); font-weight: 600; }

/* ===== Tool page (parser) ===== */
.tool-header { padding: 40px 0 12px; }
.tool-header h1 { font-size: 1.9rem; margin: 0 0 8px; color: #0f172a; }
.tool-header p { color: var(--text-muted); margin: 0; }
.breadcrumb { font-size: 0.85rem; color: var(--text-muted); margin-bottom: 8px; }
.breadcrumb a { color: var(--text-muted); }

.panel-box { background: var(--card-bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); }
.panel-box h4 { margin: 0 0 12px; font-size: 0.95rem; text-transform: uppercase; letter-spacing: 0.02em; color: var(--text-muted); }

textarea, input[type=text], select {
  width: 100%; font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  font-size: 0.92rem; padding: 10px 12px; border: 1px solid var(--border); border-radius: 8px;
  background: #fbfcfe; color: var(--text); resize: vertical;
}
textarea { min-height: 160px; }
label { font-weight: 600; font-size: 0.88rem; display: block; margin-bottom: 6px; }
.field { margin-bottom: 14px; }
.row { display: flex; gap: 12px; flex-wrap: wrap; }
.row > * { flex: 1; min-width: 140px; }

.btn { display: inline-flex; align-items: center; gap: 6px; background: var(--primary); color: #fff; border: none; padding: 10px 18px; font-size: 0.92rem; font-weight: 600; border-radius: 8px; cursor: pointer; margin: 4px 6px 4px 0; }
.btn:hover { background: var(--primary-dark); text-decoration: none; }
.btn.secondary { background: #fff; color: var(--primary); border: 1px solid var(--primary); }
.btn.secondary:hover { background: var(--primary-light); }
.btn.ghost { background: transparent; color: var(--text-muted); border: 1px solid var(--border); }
.btn.ghost:hover { background: var(--bg); }
.btn-row { margin: 14px 0; }

.status { margin-top: 12px; padding: 10px 14px; border-radius: 8px; font-size: 0.88rem; font-weight: 600; display: none; }
.status.show { display: block; }
.status.ok { background: #ecfdf3; color: var(--success); border: 1px solid #bbf7d0; }
.status.err { background: #fef2f2; color: var(--danger); border: 1px solid #fecaca; }

.hint { font-size: 0.8rem; color: var(--text-muted); margin-top: 6px; }

/* TLV output table */
.tlv-table { width: 100%; border-collapse: collapse; font-size: 0.86rem; }
.tlv-table th { text-align: left; padding: 8px 10px; border-bottom: 2px solid var(--border); color: var(--text-muted); font-size: 0.75rem; text-transform: uppercase; }
.tlv-table td { padding: 8px 10px; border-bottom: 1px solid var(--border); vertical-align: top; }
.tlv-table tr:hover { background: var(--primary-light); }
.tlv-tag { font-family: monospace; font-weight: 700; color: var(--primary); white-space: nowrap; }
.tlv-len { font-family: monospace; color: var(--text-muted); white-space: nowrap; }
.tlv-value { font-family: monospace; word-break: break-all; max-width: 320px; }
.tlv-name { font-weight: 600; }
.tlv-desc { color: var(--text-muted); font-size: 0.82rem; }
.tlv-depth-indent { display: inline-block; }
.tlv-constructed-badge { display: inline-block; font-size: 0.68rem; font-weight: 700; text-transform: uppercase; background: var(--primary-light); color: var(--primary); padding: 1px 6px; border-radius: 999px; margin-left: 6px; }
.tlv-unknown { color: var(--warn); font-style: italic; }
.tlv-decode-btn { font-size: 0.72rem; padding: 3px 9px; border: 1px solid var(--primary); color: var(--primary); background: #fff; border-radius: 6px; cursor: pointer; }
.tlv-decode-btn:hover { background: var(--primary-light); }

/* Bit-level decode panel */
.bit-decode { margin-top: 6px; padding: 12px; background: #fbfcfe; border: 1px dashed var(--border); border-radius: 8px; display: none; }
.bit-decode.open { display: block; }
.bit-decode h5 { margin: 0 0 8px; font-size: 0.8rem; color: var(--primary); }
.bit-row { display: flex; justify-content: space-between; gap: 10px; padding: 3px 0; font-size: 0.82rem; border-bottom: 1px dotted var(--border); }
.bit-row:last-child { border-bottom: none; }
.bit-row .bit-label { color: var(--text); }
.bit-row .bit-state { font-weight: 700; }
.bit-row .bit-state.set { color: var(--success); }
.bit-row .bit-state.unset { color: var(--text-muted); }